Shoots erect, indeterminate, 12--20 cm, becoming long-decumbent, 4--20 cm; leaves in mature portion slightly smaller than in juvenile portion; distinct annual constrictions present; juvenile growth erect. Leaves reflexed (juvenile portion) or spreading to reflexed (mature portion), light green to whitish green, lustrous; largest leaves oblanceolate, broadest at 1/2--3/4 length, 6--10 mm; smallest leaves narrowly triangular, broadest at base, 4--7 mm; margins with small papillae; stomates present on both surfaces, numerous (36--80 per 1/2 leaf) on adaxial surface. Gemmiferous branchlets produced in 1 pseudowhorl at end of annual growth; gemmae 4--4.5 X 3.5--4 mm; lateral leaves broadly obtuse, widest above middle, 1.25--1.5 mm wide. Spores 30--38 µm.

Terrestrial in shaded conifer forests and swamps, often along streams and in marshes; 10--1000(--2000) m; Alta., B.C., Yukon; Alaska, Idaho, Mont., Oreg., Wash.

Huperzia occidentalis is similar to the eastern H . lucidula and occupies similar habitats.